In for the long vaccine game, Merck buys into patch delivery tech with pandemic potential
When Merck dived into the R&D fray for a Covid-19 vaccine earlier this week, execs made it clear that they’re not necessarily looking to be first — with CEO Ken Frazier throwing cold water on the hotly-discussed 12- to 18-month timelines. But when it does emerge from behind, the pharma giant clearly expects to play a significant part.
Part of that will depend on next-generation delivery technology that reshapes the world’s imagination of a vaccine.
Working with Vaxxas, a longtime partner based in Brisbane, Australia, Merck has nominated the first vaccine candidate they want to deliver through the needle-free device. Having handed over $12 million in upfront investment and fees, Merck is also entitled to two additional licenses.
While the partners stayed tight-lipped about the candidate or the disease it seeks to prevent, Vaxxas emphasized that the technology — with its potential for self-administration, stability at high temperatures and lower dosage requirements — could be “game-changing” in pandemic situations.
Speaking from his home in Boston, Vaxxas CEO David Hoey told Endpoints News that the idea is predicated on the observation that the greatest density of immune cells lie just under the surface of the skin.
“So if you scratch your skin with a stick when you’re walking, you pretty instantly see a red mark,” he said. “The initial inflammation enables the immune cells to migrate and to see whether or not there is any invader, if you like, that is present, any foreign entity. And we leverage that.”
Within each Vaxxas patch, which bears resemblance to a small tub of ointment, are thousands of short projections that would send vaccine antigens just there for immune cells to take directly to the lymph nodes.
The mechanism renders it much more potent, he added, than conventional delivery. In a human trial comparing a traditional flu shot to one delivered by the Vaxxas patch, they found that they were able to induce a comparable immune response with a sixth of the dose.
Despite the promise, though, skin vaccination has largely been confined to academic labs because of the difficulty to manufacture at scale.
“You can make 5 or them or 50 of them to do experiments in animals, but can you make 50 million of them?” he said.
Vaxxas also has academic roots, starting out with scientific exploration involving Merck’s vaccines. But since 2011, the company has ramped up its process to the point where it can make 1,000 patches per day. The target is to get to 1 million per week — a scale it hopes to reach in two and a half years through a new alliance with Harro Höfliger.
Merck, which had secured approval for its record-setting Ebola vaccine just before the Covid-19 outbreak in China took place, bagged two development candidates overnight by acquiring one company and collaborating with a nonprofit. The first, from Austrian biotech Themis, comes from a measles virus vector-based platform; the second is developed by IAVI and benefits from the same technology as the Ebola immunization.
Theoretically, both could be amenable to skin patch delivery using Vaxxas’ tech, Hoey said: “The patch is vaccine agnostic.”